Fractional flow in fractured chalk; a flow and tracer test revisited.

N E Odling, L J West, S Hartmann, A Kilpatrick

School of Earth and Environment, University of Leeds, Woodhouse Lane, Leeds LS1 9JT, UK. n.odling@see.leeds.ac.uk

Journal of contaminant hydrology 2013 Apr

filter terms:

A multi-borehole pumping and tracer test in fractured chalk is revisited and reinterpreted in the light of fractional flow. Pumping test data analyzed using a fractional flow model gives sub-spherical flow dimensions of 2.2-2.4 which are interpreted as due to the partially penetrating nature of the pumped borehole. The fractional flow model offers greater versatility than classical methods for interpreting pumping tests in fractured aquifers but its use has been hampered because the hydraulic parameters derived are hard to interpret. A method is developed to convert apparent transmissivity and storativity (L(4-n)/T and S(2-n)) to conventional transmissivity and storativity (L2/T and dimensionless) for the case where flow dimension, 2porosity model of solute transport incorporating matrix diffusion and modified for fractional flow. Model results show smaller fracture apertures, spacings and dispersivities than those when 2D flow is assumed. The pumping and tracer test results and modeling presented illustrate the importance of recognizing the potential fractional nature of flow generated by partially penetrating boreholes in fractured aquifers in estimating aquifer properties and interpreting tracer breakthrough curves. Copyright © 2013 Elsevier B.V. All rights reserved.

Citation

N E Odling, L J West, S Hartmann, A Kilpatrick. Fractional flow in fractured chalk; a flow and tracer test revisited. Journal of contaminant hydrology. 2013 Apr;147:96-111